For example, lets see up until now, your team has pitched 10 innings and has allowed 10 (hits + BB) for a WHIP of 1. Rodney pitches tonight, giving up 2 BB while recording 0 Inn. So now you have 10 innings and 12 (Hits +BB) for a WHIP of 1.2 .
Thats how it works. You probably had way more then 10 innings for the week so the difference wouldnt have mattered, like 42 BB+H over 40 innings isnt that much different than 40 BB+H over 40 innings.
Dodgers World Champs 2012